phy
As a student walks downhill at constant speed, his gravitational potential energy (1) increases and his kinetic energy increases (2) increases and his kinetic energy remains the same (3) decreases and his kinetic energy increases (4) decreases and his kinetic energy remains the same
(4) decreases and his kinetic energy remains the same
Which pair is classified as a substance?
1. compounds and mixtures
2. elements and compounds
3. elements and solutions
4. elements and mixtures
2. elements and compounds
After ingesting Vitamin D, the body converts it into a hormone that is transported throughout the body. This hormone affects cells in the intestines and bones. The reason that this hormone affects only certain cells in the body is because these cells have (1) specific receptors (3) specific organelles (2) antibodies (4) genes
(1) specific receptors
The sum of three consecutive odd numbers is 57. Find the numbers.
The three consecutive odd numbers are 17, 19, and 21. 2x+1+2x+3+2x+5=57
The day before two days after the day before tomorrow is Saturday. What day is it today?
Friday. The “day before tomorrow” is today; “the day before two days after” is really one day after. So if “one day after today is Saturday,” then it must be Friday.
For an object moving in uniform circular motion, the direction of the instantaneous acceleration vector is:
-tangent to the path of motion
-equal to zero
-directed radially outward
-directed radially inward
-directed radially inward
Describe the difference between an ionic and covalent bond
Ionic bonds involve the transfer of electrons between atoms, while covalent bonds involve the sharing of electrons between atoms.
Most scientists agree that a large asteroid struck Earth around 65 million years ago. The impact sent large amounts of fine dust particles into the atmosphere, which reduced the amount of sunlight reaching the planet. This event would have the most immediate effect on (1) herbivores (3) carnivores (2) decomposers (4) autotrophs
autotrophs
Susan and Lisa decided to play tennis against each other. They bet $1 on each game they played. Susan won three bets and Lisa won $5. How many games did they play?
Eleven. Because Lisa lost three games to Susan, she had lost $3 ($1 per game). So, she had to win back that $3 with three more games, then win another five games to win $5.
There are three people (Alex, Ben and Cody), one of whom is a knight, one a knave, and one a spy. The knight always tells the truth, the knave always lies, and the spy can either lie or tell the truth. Alex says: "Cody is a knave.” Ben says: "Alex is a knight.” Cody says: "I am the spy.” Who is the knight, who the knave, and who the spy?
We know Ben isn’t telling the truth because if he was, there would be two knights; so Ben could be either the knave or the spy. Cody also can’t be the knight, because then his statement would be a lie. So that must mean Alex is the knight. Ben, therefore, must be the spy, since the spy sometimes tells the truth; leaving Cody as the knave.
A 5.0-kilogram box is sliding across a level floor. The box is acted upon by a force of 27 newtons east and a frictional force of 17 newtons west. What is the magnitude of the acceleration of the box? (1) 0.50 m/s^2 (3) 8.8 m/s^2 (2) 2.0 m/s^2 (4) 10. m/s^2
(2) 2.0 m/s^2
let the function f be defined by 𝑓(𝑥)=𝑥^2+18. If a is a positive number such that 𝑓(2𝑎)=3𝑓(𝑎), what is the value of a?
6
You are given three doors to choose from, one of which contains a car and the other two contain goats. After you’ve chosen one but haven’t opened it, Monty, who knows where everything is, reveals the location of a goat from behind one of the other two doors. Should you stick with your original choice or switch, if you want the car?
You should switch. At the beginning, your choice starts out as a one in three chance of picking the car; the two doors with goats contain 2/3 of the chance. But since Monty knows and shows you where one of the goats is, that 2/3 chance now rests solely with the third door (your choice retains its original 1/3 chance; you were more likely to pick a goat to begin with). So, the odds are better if you switch.